The present invention relates to a product and method for producing a curved surface composite material wherein a thermoset composite is manufactured containing a paper overlay characterized in that the paper is pressed into the composite material a desired amount, without rupturing or tearing of said overlay in the molding process. Accordingly, the present invention provides a composite material with a paper overlay characterized in that the paper is readily pressed into grooves in the composite, therein providing the ability to manufacture a composite material ideally suited for such applications as the preparation of a composite tile panel, with a decorative overlay design.
In the context of the present invention, it is noted that molded thermoset products are well known in the art, specifically, products manufactured from plastic materials generally known as amino resins, or phenolic resins and the like. Such thermoset materials ordinarily are molded by the techniques of compression molding, given the fact that such resins are in fact commercially available as molding powders and are known to cure in the presence of heat to provide a crosslinked material of relatively high strength and stiffness. In accordance with the manufacture of such resins by such procedures, it is common to incorporate various fillers and additives, to both improve the processing characteristics and to improve or modify the properties of the resins after they are cured.
In addition, laminates of the above resins have been prepared, wherein a decorative laminate made or derived from paper, is bonded or adhered to the resin during cure and molding. Typically, the paper itself is porous, and may contain some of the resin so that it binds chemically to the molded product and provides a decorative aspect not available by the resin on its own.
However, numerous problems have been encountered in regards to preparing curved surfaces, as it can be appreciated that in the molding process, the laminate would necessarily have to remain protruding over the edge of the molding powder to be curved, in order to provide the necessary surface area to cover the final molded product on its edge side. Conventional compression molds do not accommodate such overlapping paper laminate, and if the paper is allowed to sit on top of the molding powder in a conventional compression mold design, the paper will be pinched by the mold cavity itself prior to being drawn into the mold and associated or bonded with the curved edge and incorporated into the molded product.
In addition, one long-standing problem with the production of a curved surface laminate, although such problem also exists in non-curved products, is the preparation of a laminate containing integral reinforcing type ribs which themselves contain an insert in the rib for receipt of a screw or other attachment means to connect to a frame. That is, the prior art to date has not been able to successfully incorporate such inserts into composite materials during molding thereof.
Therefore, it is an object of the invention to overcome the disadvantages of the prior art and provide both a mold design which allows for a decorative laminate overlay to be drawn into the mold during the molding cycle without being stretched or torn in the overall molding process.
More specifically, it is an object of the invention to provide a mold for the compression molding of thermoset polymer resins, although other resins are contemplated, including thermoplastic resins, wherein the mold contains a region for the placement of an overlapping paper laminate, that can be drawn into the mold, and applied to a curved surface, in a manner that does not stretch or tear the laminate paper material.
Furthermore, it should be noted that it is an object of the present invention to prepare an integrally molded product having a curved surface, characterized in that the product is formed of a polymer or plastic material, and a laminating layer is affixed to the polymer or plastic material, in an integral manner.
Finally, it is also an object of this invention to prepare a composite material part containing a performed insert which becomes part of the molded part and produces a site for attachment of said part to a frame or similar structure.
A molding press for simultaneously molding a product and laminating a pattern layer to the surface of the molded product comprising a bottom mold plate, a top mold plate, a mold ring element surrounding the mold plates and moveable independently of the top and bottom mold plates, an upper surface on said mold ring for engaging a peripheral edge of the top mold plate, and a flat groove in said mold ring upper surface which is slightly deeper than the thickness of a pattern layer to be laminated to the top surface of the final molded product.
In process form, the present invention provides a process for simultaneously molding a product and laminating a pattern to the surface of the molded product comprising the use of a mold having a bottom mold plate, a top mold plate, a mold ring element surrounding the mold plate and moveable independently of the upper and lower mold plates, wherein the edges of said top mold plate overlap an inner portion of the mold ring element providing a flat space between adjacent surfaces of the said mold plate and said mold ring element, followed by supporting said pattern layer at its edges in said flat space while maintaining the space slightly thicker than the thickness of the pattern layer so that said layer is free to slide laterally across the upper surface of said mold ring towards the mold interior during the molding process, followed by filling the volume provided by the lowered bottom mold plate and the mold ring to the level of the inner edge of the mold ring with a heat setting molding powder, raising said lower mold plate to compress and cure the molding powder and laminating said pattern to the upper surface of said cured molded product.
In product form, the present invention comprises and integral molded product having a curved surface to which is bonded a pattern layer, said molded product being formed of a heat curable reactive polymer resin and said pattern layer including a porous structure into which said reactive polymer resin penetrates and cures to unify or bond the pattern layer and the curved molded project surface.
In addition, the present invention discloses an integral formed molded product said molded product being formed of a heat curable reactive polymer resin containing an integrally formed reinforcing rib including an insert in said rib which bonds to said heat curable reactive polymer resin during molding thereof, and which insert provides means for attaching said integrally formed product to a frame or support structure.
In addition, in further alternative embodiment, the present invention is directed at an integral formed molded product with a convex surface, said molded product being formed of a heat curable reactive thermoset polymer resin molding powder containing an integrally formed insert which bonds to said heat curable reactive thermoset polymer resin during molding thereof, and which insert provides attachment of said integrally formed product to a frame or support structure, including a boss with a top projecting from said convex surface, a supporting feature supporting said boss which supporting feature extends from the top of said boss to said convex surface.
Finally, in alternative embodiment, the present invention is directed at a method for forming an integral formed molded product with a convex surface, comprising supplying a heat curable reactive thermoset polymer resin molding powder, supplying an insert which bonds to said heat curable reactive thermoset polymer resin, supplying a mold with a convex shape including openings to receive said insert during molding thereof, securing said insert to said mold wherein said mold includes a cavity which forms a boss on said molded product which boss projects from said convex surface, said cavity forming a supporting feature supporting said boss which supporting feature extends from the top of said boss to said convex surface, and curing said heat curable reactive thermoset polymer resin molding powder to formed said product.